1. Field of the Invention
The invention relates to a basic input/output system (BIOS) of a computer, more particularly to a computer screen image displaying method for execution by a basic input/output system of a computer having a vertical display device.
2. Description of the Related Art
With the fast development of computer technology, current computers and their peripheral equipment are capable of providing users with various choices and meeting users' requirements in various operations. For instance, a vertical display screen enables a user to view more content when browsing a document or a web page through a computer display screen.
In conventional methods which permit switching between landscape and portrait display modes, display signals are rotated before being outputted primarily through use of software. This, however, means relatively heavy workloads on the central processing unit of a computer.
In recent years, settings of the operating system of a computer can be modified to enable a video controller to change screen orientation. The video controller will rotate text and images during display processing so that the text and images are displayed in a portrait orientation. However, all of the above methods of rotating a display screen require the user to make the settings under an operating system environment after selecting a desired screen orientation, and execution of the settings by the operating system involves much time and considerable system resources. For a display device that is specifically designed to operate in a portrait display mode, conventional portrait display methods are evidently not better solutions.